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White Spots On Orchid Leaves (Causes And Treatments)

Even the tiniest white spots on an orchid’s leaves are a clear sign that the epiphyte is in trouble. To assist the orchid in a timely manner, it is necessary to first understand the true causes of their appearance.

The wrong kind of maintenance is putting fuel on the problem. As a result, you may see various symptoms of the disease on your orchid’s leaves, one of which is the appearance of white spots on the orchid’s leaves.

Why do Orchid Leaves Get White Spots? I will help you identify the problem using external signs and clear photographs. 

In addition, I’ll explain how to get rid of white spots and how to prevent them in the future.

Why Are The White Spots On Orchid Leaves?

Phalaenopsis orchid leaves may have white spots due to improper watering and lighting conditions. An infection may be caused by a virus or an insect.

Inappropriate Watering Methods

White Spots on Orchid Leaves Due to Overwatering
White Spots on Orchid Leaves Due to Overwatering

When an orchid has white leaves, it is most likely due to an epiphyte that has been overwatered. 

As far as watering is concerned, the most important rule is to allow the plants to dry out between waterings, but to water them thoroughly when necessary.

Overwatering can be particularly harmful to orchids. When watering, take care to avoid submerging the tips of the lower leaves.

Long-term exposure to moisture can cause oval white spots on the leaf with a notch in the middle.

Insufficient Humidity In The Room

Pebble Tray Helps Increase Himidity

When there is no chance of overwatering, how can an orchid have white leaves?

As a result of low humidity and insufficient watering, the orchid is at risk of drying out. So, white spots with dark surroundings can appear on the leaves.

Even if the situation is corrected in time, the orchid will not be able to regain its former aesthetically pleasing appearance.

Frostbite or Scorch on The Leaves

Sunburned Orchid Leaves
Sunburned Orchid Leaves

Burns can also occur as a result of prolonged exposure to the sun. In the spring and summer, ultraviolet light is particularly harmful.

Leaves with water droplets on them can act as a magnifying glass, doubling or tripling the sun’s rays. 

The leaf plates may develop dry white spots with a dark outline.

Make sure that the leaflet isn’t hot to the touch by doing as follows.

Take out the orchid and place it in the center of the room by covering it in translucent paper, blinds, or curtains. The flower thrives best on a window sill with diffused light.

If the situation is corrected in time, the orchid will not be able to return to its previous aesthetic appearance.

Frosty air currents are equally hazardous to phalaenopsis. Exposure to cold during transportation or a brief opening of a window can suffice in some cases. As a result, the orchid will start to develop yellow-white soggy spots.

Frostbite Causes White spots on Orchid Leaves
Frostbite Causes White spots on Orchid Leaves

Orchids can get frostbite at temperatures below 30s (0°C) Keep the plant’s leaves away from the windowsill’s cold glass.

White Spots on Leaves Due to Powdery Mildew

In the case of an orchid that develops white spots on its leaves, it is likely that the plant has been infected with a fungal infection known as powdery mildew.

A series of tiny spots appear at first and then multiply, turn yellow-gray, and finally start to dry out. It takes a few days for these leaves to die off.

Orchid Leaves Turning White Due to Powdery Mildew
Orchid Leaves Turning White Due to Powdery Mildew

The following factors contribute to the growth of the fungus on the plant:

  • Nitrogen fertilizer oversaturation of the substrate.
  • Watering was not properly scheduled.
  • Humidity is high.
  • Intense fluctuations in temperatures.

The pathogenic fungus is more likely to spread to plants with low resistance.

Mealybug Infestation

They are small insects 3-6 mm in size. The pest leaves specific white secretions on the leaves. 

If mealybug colonies have colonized your orchid, the leaves may turn white. Thick, sticky secretions and cottony lumps are telltale signs of this pest.

Some tiny pests like aphids, spider mites prefer the axils and the back of the leaf surface. 

Insect colonies spread throughout the plant, including the roots, eventually becoming a major problem for your orchid.

The most common causes of mealybug infestation in orchids include:

  • Low humidity levels;
  • Overwatering of the substrate on a regular basis;
  • Chilly temperatures;
  • Over-application of nitrogen fertilizers.

On top of that, pests can be transferred from a new flower specimen to your clothing or other items.

Diseases caused by viruses

Orchid Leaves Turning White Due to Virus Infection
Orchid Leaves Turning White Due to Virus Infection

There are approximately 20 different types of viruses in the orchid world.

The tricky part about viral diseases is that they can be difficult to detect. The disease may go undetected for a long time before spreading to all of your orchids in your home.

You can have the plant virus-tested (if the plant is valuable to you). However, if it is a virus, there is no cure. 

It, along with the pot and media, should be discarded. Also, do not share cutting tools between plants; instead, use a new razor blade for each plant or a sterilized tool. 

Sterilization can be accomplished using a flame or harsh chemicals such as 50% bleach and water or a saturated solution of trisodium phosphate (TSP) in warm water. Disinfect used pots as well.

Phalaenopsis leaves are commonly infected with the following viruses:

[1] Cymbidium mosaic virus (CymMV) infects plants via cuttings and insect bites. White spots with stripes appear on the backs of leaves. Do not respond to treatment.

[2] Phalaenopsis chlorotic spot virus (PhCSV). Disrupts the formation of chlorophyll in plant cells, reducing the amount of photosynthesis that occurs. 

Initially, leaves are covered in pink and yellow spots, which eventually fade to white. 

Cattleyas, Phalaenopsis, and Dendrobiums are particularly vulnerable. The orchid can be cured if there is only a minor infestation.

[3] An orchid fleck virus (OFV). Older leaf blades are more likely to have this symptom. Circles, dots, and stripes cover their inner surface. 

After some time, the spots become grayish-white in color. Viruses are often accompanied by fungus, which causes the infected areas to turn black.

[4] Taiwan-Virus or Capsicum chlorosis virus (CaCV). The majority of the time, it prefers young Phalaenopsis seedlings as food. 

When viewed closely, a few small, light white spots can be seen on the leaves. Flowers and buds are unaffected by this.

[5] Dendrobium mosaic virus (DeMV). Depressed white diamond-shaped spots with oval or ring-shaped blotches cover the leaves. 

It primarily attacks wild epiphytes. This is a rare occurrence in hybrid varieties. It’s not going to be treated in any way.

Plants that have been treated may still be virus carriers. It “goes dormant” for a while, but in most cases, it manifests itself again. And the plant will eventually die.

Using External Signs To Pinpoint The Exact Cause

What to do if white spots appear on the leaves of an orchid, and how to determine the cause of the ailment based on external manifestations?

This summary table can help you figure out what’s causing your orchid leaves to turn yellow:

SignsCausesImages
White soggy spots and swellingOverwatering 
White sunken spotsUsing city tap water
White spots with a black circleKeeping orchid in direct sunlight or near a lamp
White fuzzy spotsMealybugs infestation
White dots on the leavesTemperature too Low
Leaves and stem turned whitePowdery mildew
White stripes on the leavesViral Diseases
White stripes along with the leafCracks in the leaves due to overwatering
Hollowed out white dotsDamage after rain or hail

A quick diagnosis will help you treat your orchid faster and prevent infection of nearby plants.

How to Get Rid of White Spots

As a first step, you’ll need to fundamentally alter your orchid’s plant’s care practices. And, if necessary, implement an extensive treatment.

Recovery from Over-watering

If the plant has been in a wet substrate for an extended period of time, the following steps must be taken:

  • Remove the plant from its pot with care.
  • Remove the roots from the soil.
  • Inspect the flower and remove any rotten or injured areas.
  • Use charcoal powder to treat the wounds.
  • Allow drying on its own.
  • Plant in a new pot with fresh soil.

There is no way to repair leaf plates with white spots. Cut them off with a sterile knife and disinfect the cut with cinnamon or charcoal. This will enhance the flower’s visual appeal.

How to Recover Sunburned Orchid

As soon as the orchid’s leaves begin to turn white in the sun, it’s time to move the epiphyte to a shady location and adjust the watering of the substrate.

Do not fertilize your orchid until it has fully recovered from its previous injuries.

If the spot is in the center, wait until the leaf is completely dry before removing it.

Caring For An Over-Dried Orchid

You must get your orchid back to its normal watering schedule to stop the wilting process.

Rates of watering:

  • In the summer, approximately 2-3 times per week; 
  • In the winter, no more than 1-2 times every 7 days.

If it’s a hot summer, you can increase the frequency of watering. The substrate in an orchid pot should always be slightly moist.

The best way to water an orchid is to submerge it in water:

  • Fill a container halfway with clean, room-temperature water.
  • Immerse the orchid vase in the liquid; water should flow to the substrate through the holes at the bottom of the pot. The orchid’s neck should be completely dry.
  • Allow for 10-20 minutes of standing time.
  • Remove the pot from the water and allow the remaining liquid to drain.

This way, the bark will be completely saturated with water and will be able to provide moisture to the plant for an extended period of time.

Powdery Mildew Treatment

If the leaves of the orchid develop white spots resembling powdery mildew, the infected shrub must be quarantined from the other Phalaenopsis.

To save the flower, take the following steps:

  • Using a cotton pad soaked in a laundry soap solution, clean the white spots on the leaf plates.
  • Remove infected plant parts.
  • Apply cinnamon or ground charcoal to the wounds.
  • Replace the top layer of the substrate with a new substrate.

It is possible to slow down the spread of the infection by making these simple adjustments.

You can use one of the following folk remedies for controlling the initial infestation of fungus:

  • 25 g garlic, finely chopped, 1-liter water, strain the mixture after a day, and use it for watering;
  • 10 g of ash dissolved in 95°F/35 °C water, strain after 5-7 days, and add a little liquid soap – spray it 3 times a day;
  • 1 tbsp baking soda and 0.5 tsp liquid soap in 4 liters of water – treat 2-3 times every 6-7 days;
  • Dissolve 1-2 tbsp mustard powder in 10 l of warm liquid, then spray the cooled mixture;
  • Water 2-3 times every 5 days with 25 g manganese dissolved in 5 liters of water.

Such treatments are only effective in the early stages of powdery mildew development.

For the treatment of fungal diseases. Here are the fungicides I recommend:

Name of The FungicideAmountAmount of Water
Bonide 811 Copper 4E Fungicide1-4 tablespoons (.05-2.0 fl oz)1 gallon of water
Garden Safe Brand Fungicide32 tablespoons (1 fl oz) 1 gallon of water
Southern Ag – Liquid Copper Fungicide3-4 tablespoons1 gallon of water

Spray the infected orchid foliage to remove the disease. Repeat in 10-14 days.

Apply pesticides with caution and basic safety precautions, such as wearing rubber gloves, a mask, and goggles. Treatment should take place outside or on a roof.

Mealybug Control

If you notice any white hairy spots on the orchid, you have a mealybug infestation.

Cutting off the damaged stems and leaves is a good first step in dealing with an infestation. 

Clean any visible mealybugs from your orchid with a cotton swab or a pair of forceps.

Wipe the leaves with soapy water and rinse the plant under warm running water.

If only one pest has infested the Phalaenopsis, you can try these folk remedies:

  1. Garlic tincture Pour 0.2 l of boiling water over 5 garlic cloves and crush them. Make sure the mixture is completely cooled before adding water in a 1:1 ratio. Apply to the affected areas by rubbing and spraying.
  2. Infusion of onions Add 250 ml of warm water to a medium onion head and chop it finely. Filter the tincture after 5-6 hours of infusion. As a watering solution, use this mixture once every seven days.
  3. Pepper solution Boil 500 ml of water and add 50 grams of chilies. After 5 minutes of boiling, remove from heat and allow to cool. After filtering, the broth is ready to use.
  4. Oil Emulsion Add 60 ml of olive oil to 1 liter of water and mix thoroughly. Rub the infected leaf areas with the solution.

Such treatments will be ineffective against a large number of pests. To completely eradicate mealybugs, you must use one of the following fungicides:

Name of The FungicideAmountAmount of Water
Bonide 811 Copper 4E Fungicide1-4 tablespoons (.05-2.0 fl oz)1 gallon of water
Garden Safe Brand Fungicide32 tablespoons (1 fl oz) 1 gallon of water
Southern Ag – Liquid Copper Fungicide3-4 tablespoons1 gallon of water

After 2-3 weeks, repeat the treatment. Use pesticides on the orchid in a separate, well-ventilated room away from the house. 

Wear a respirator, gloves, and goggles to protect your skin and respiratory system from the toxicity of the preparations.

Preventing White Spots on Orchid Leaves

You can eliminate white spots on the leaves of an orchid by re-creating the ideal conditions for growth:

  • Keep to a regular watering schedule depending on the season and growth stage;
  • When applying complex fertilizers, be sure to do so on time. Once in a month.
  • Ensure that the plant receives enough diffused sunlight.
  • Keep an eye on the temperature of your home.
  • Quality substrate and drainage should be used when replanting a plant.
  • Protect the plant from the harmful effects of ultraviolet light.

Having regular check-ups will allow you to catch problems before they become serious. 

You can save the plant from catastrophic consequences and the death of your orchid if you act quickly.